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What does a b prefix before a python string mean?
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This is Python3 bytes literal. This prefix is absent in Python 2.5 and older (it is equivalent to a plain string of 2.x, while plain string of 3.x is equivalent to a literal with u prefix in 2.x). In Python 2.6+ it is equivalent to a plain string, for compatibility with 3.x.
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How is pattern matching in Scala implemented at the bytecode level?
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case Sum(l,r) // instance of check followed by fetching the two arguments and assigning to two variables l and r but see below about custom extractors
case "hello" // equality check
case _ : Foo // instance of check
case x => // assignment to a fresh variable
case _ => // do nothing, this is...
How do I update the notification text for a foreground service in Android?
I have a foreground service setup in Android. I would like to update the notification text. I am creating the service as shown below.
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Executing periodic actions in Python [duplicate]
... One thing to watch out for here is start time "drift". I just ran a test and my times drifted by +0.05s in about 33 iterations. I was running 1 second polls, and this means a drift of 20% in less than a minute. You can reduce drift by calling the threading.Timer at the start of the function rather...
MongoDB: update every document on one field
... all of these instances of foo. After running that I do a db.foo.findOne() and lastLookedAt is: 1327691719186, which translates to jruby-1.6.5 :011 > Time.at(1327691719186) => Sun Nov 16 02:19:46 -0500 44042
– randombits
Jan 27 '12 at 19:16
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Determine if Python is running inside virtualenv
...nside a virtual environment, sys.prefix points to the virtual environment, and sys.base_prefix is the prefix of the system Python the virtualenv was created from.
The above always works for Python 3 stdlib venv and for recent virtualenv (since version 20). Older versions of virtualenv used sys.real_...
Adding a column to a data.frame
...xt, [[.data.frame.
Data frames can be indexed in several modes. When [ and [[ are used with a single vector index (x[i] or x[[i]]), they index the data frame as if it were a list.
my.dataframe["new.col"] <- a.vector
my.dataframe[["new.col"]] <- a.vector
The data.frame method for $, ...
ObservableCollection Doesn't support AddRange method, so I get notified for each item added, besides
I want to be able to add a range and get updated for the entire bulk.
12 Answers
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How does a Linux/Unix Bash script know its own PID?
I have a script in Bash called Script.sh , and it needs to know its own PID (i.e. I need to get PID inside the Script.sh )
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Java: How to test methods that call System.exit()?
...n normal use it will drift all the way out to the JVM's last-ditch catcher and shut your script down (unless you decide to catch it somewhere along the way, which might be useful someday).
In the JUnit scenario it will be caught by the JUnit framework, which will report that
such-and-such te...